The basic theory and operation of thermoelectric devices has been developed for many years. Presently available thermoelectric devices used for cooling typically include an array of thermocouples that operate in accordance with the Peltier effect. Thermoelectric devices may also be used for heating, power generation, and temperature sensing.
A thermoelectric device produces electrical power from heat flow across a temperature gradient. As the heat flows from hot to cold, free charge carriers in the thermoelectric material are also driven to the cold end. The resulting voltage is proportional to the temperature difference via the Seebeck coefficient.